Tap water scalds and the water heater setting

Most people hurt or killed by scalding tap water are older adults and children under 5. Water at 150°F gives most adults a third-degree burn in 2 seconds, and water at 140°F does it in 6. Setting the water heater to 120°F cuts the risk of most tap water scalds and uses less energy too.

What you need

• A candy or meat thermometer
• The phone number of your electric or gas company, or of your building manager

Steps

1. 1

   Wait until the hot water has sat unused

   Measure first thing in the morning, or at least 2 hours after anyone last ran the hot water.

   5 min

2. 2

   Measure at the faucet

   Run the hot water at the kitchen tap and hold a candy or meat thermometer in the stream until the reading stops climbing.

   5 min

3. 3

   Have the setting lowered if it reads above 120°F

   For an electric heater, call the electric company, since some set it at no charge. Most electric heaters have two thermostats behind access panels, and both need the same setting. For a gas heater, call the gas company.

   15 min

4. 4

   Measure again the next morning

   If the reading is still high, have the setting adjusted again and check once more.

   5 min

5. 5

   Ask about a home without its own water heater

   If the hot water comes from the furnace or boiler, ask the fuel supplier to lower it. In an apartment, ask the building manager.

   10 min

Set the heater to the lowest temperature that still meets the house's needs, including the washing machine and the dishwasher. A lower setting saves energy and money as well as preventing burns. On a home heated by a furnace that also makes the hot water, a lower water temperature doesn't change how well the furnace heats the house.

Water heater upkeep covers the yearly flush and the relief valve test.